In its message of 30 May 1997 the Universal House of Justice announced that they have authorized the formation of "State Bahá'í Councils" or "Regional Teaching and Administrative Committees" to be called "Regional Bahá'í Councils. Their intention was to provide a balance between centralization and decentralization. This structure had been in place in some countries, notably India, for some years prior to this time. See 23 May, 1986. [TP87-90]
For a synopsis of the letter see The Establishment of Regional Bahá'í Councils in Certain Countries, Their Characteristics and Functions.
The distinguishing effects of the establishment of Regional Bahá’í Councils are the following:

It provides for a level of autonomous decision making on both teaching and administrative matters, as distinct from merely executive action, below the National Assembly and above the Local Assemblies.

It involves the members of Local Spiritual Assemblies of the area in the choice of the members of the Council, thus reinforcing the bond between it and the local believers while, at the same time, bringing into public service capable believers who are known to the friends in their own region.

It establishes direct consultative relationships between the Continental Counselors and the Regional Bahá’í Councils.

It offers the possibility of forming a Regional Bahá’í Council in an ethnically distinct region which covers parts of two or more countries. In such a situation the Council is designated to work directly under one of the National Assemblies involved, providing copies of its reports and minutes to the other National Assembly.

The greater degree of decentralization involved in the devolution of authority upon Regional Bahá’í Councils requires a corresponding increase in the capacity of the National Spiritual Assembly itself to keep fully informed of what is proceeding in all parts of the territory over which it has ultimate jurisdiction.

The National Spiritual Assembly of the Bahá'ís of the United States announced the results of the elections for their first Regional Councils. Four were elected in the regions corresponding to those mentioned in The Tablets of the Divine Plan.
[Results of the First Regional Bahá'í Council Election]